Thank you for these links, I wish the BBC article included them. Here's the press release from the University of Rochester, where the study was conducted:
This appears to have an interesting implication for FFI [1], a mysterious genetic disease that causes complete insomnia in adults and results in death. The final stage of FFI is dementia.
It turns out that the β-amyloids that are cleared during sleep according to this paper, are associated with certain types of dementia in the general population [2].
It also turns out that certain sleep disorders are dementia predictor [3].
This is just a laymen's speculation, but this is suggestive that dementia may be a type of sleep disorder, that it could be caused by some interruption in the process demonstrated in this paper.
And this is a stretch, but it is known that FFI is caused by a malformed prion protein, which is a protein that is deeply involved in various neuron-related functions. It seems possible that this protein is involved in the cleansing process in some way. If so, that would be a HUGE deal, because abnormal prion proteins are associated with a huge variety of neurodegenerative diseases.
To expand on the dementia issue, poor lighting can lead to disturbances in circadian rhythm and issues with sleep. Fixing this may help with dementia. Further research needed in the area.
Is it known if there are ways to support the cleanup process?
I ask because due to allergies I have constant sinus congestions and as a result a very light sleep. On average I wake up (to the point where I'm consciously aware that I'm awake) 2 to 4 times per night, persumably due to lack of oxygen.
I'm noticing memory issues; and while the process may not be reversable, I would like to halt it or at least slow it down as much as possible.
"The brain only has limited energy at its disposal and it appears that it must choose between two different functional states - awake and aware or asleep and cleaning up,"
Sure sounds like part of the wake-sleep algorithm, which is impressive given that the wake-sleep algorithm was named in the mid-90s.
Why does everyone in this thread want to get rid of sleep? I like sleeping, and dreaming. 24-7 consciousness in the name of increased productivity sounds like a nightmare, no pun intended.
How can you enjoy something you're not conscious of? What you likely enjoy is the 5-30 minutes as you're falling asleep, and the 5-60 minutes as you're waking up.
If we could get the actual sleeping time to 1 minute, but keep the rest the same, surely that would be strictly better in terms of human utility.
Can anyone with better knowledge of such things explain why this has to occur during sleep? Is there just too much going on during the day to dedicate physical and mental resources to this type of cleaning?
I have no better knowledge, just parsing the reports:
The cleanup is more effective during sleep because the channels that transport waste from the brain expand 60% in volume, and the brain cells themselves shrink by a similar amount to make room.
I suppose that the brain cells can't shrink that much while retaining their full function.
> [Dr Nedergaard] told the BBC: "This is purely speculation, but it looks like the brain is losing a lot of energy when pumping water across the brain and that is probably incompatible with processing information."
Fascinating. An average 60 year old man sleeps for 20 years (considering a normal 8 hr a day sleep) that is 1/3 of his life. A polar bear and some other hibernating animals sleep for half of their lives. Amazingly polar bear is cognizant enough to feed her baby while she is sleeping.
Sleep also lowers the heart beat. It is generally accepted that all mammals have the same life span in number of hear beats. An elephant lives longer than a mouse because it's heart beats slower. Could that mean that people who live longer generally sleep more.
Whales are known to live for a long time. Wonder how much they sleep.
I always wondered about how split-brain theory would work into this...
I mean there are stories of people with half their brain removed who are fully functional (I think? I can't find a source atm).
I wonder what would happen if half your brain could be on/off and switch?
Also you'd think that any mutation optimizing for time awake would have decimated the other creatures? I don't get how evolution has conquered everything but sleep.
There are actually animals that sleep half a brain at once: all the marine mammals. A dolphin can't just fall asleep underwater (it will drown), so it sleeps half at a time.
There are creatures that sleep very little (Giraffes, etc.) But there's large benefits to sleep, and for most animals it's worth the cost, especially since you don't want to burn piles of calories during non-peak hunting/foraging hours anyway.
On that post about a bird that fly for 6 months in a row there were a discussion about the sleep in animals. Some of them are able to sleep alternating one half sleeping and the other aware of the environment. And there is speculation if that bird could sleep while flying.
I think half brain awake is not enough to have a fully functional life. I also heard about people losing part of their brain and adapting to deal with it. But that doesn't mean a brain doesn't need that part. It is like the fallacy of using only 10% of the brain. The brain is very well used and optmized for performance, if you lose part of it, it would adapt to compensate what is missing, but it will not be optimized anymore.
Disclosure: just guessing here, I have no scientific knowledge or background at all to support these claims of mine.
The people who have had half their brains removed (Hemispherectomy) and are functional had it removed when they were very young and the other side wired to adapt. Depending on age of operation, there may be more or less significant impairments for life.
For humans with 2 healthy hemispheres, as far as I'm aware better imaging is revealing that split brain theory is only partially correct for many of the processes that were formerly thought to happen in one half only. Recent imaging has shown that the other half is still involved, albeit in a less widespread fashion.
>you'd think that any mutation optimizing for time awake would have decimated the other creatures?
Maybe the specialization into day/night has something to do with it. The decimator would need to stand their ground against nocturnal creatures at night and diurnal creatues at day.
Seems unlikely. Essentially all animals with a brain sleep, even flies. You'd need to find a pill that could do something that not one animal was able to evolve to do over hundreds of millions of years. Something that was extremely calorie intensive is all I can imagine.
I'd be happy with a pill that speeds up the sleep/recovery process - it seems easier to achieve and it wouldn't go against millions of years of evolution...
A "toxin" is something which is toxic to a system. But our knowledge of the brain is so primitive that we can't reasonably claim to know which chemicals are toxic at tiny, long-term dosage levels, unless it leads to death. There is no evidence that it's possible to die directly from sleep deprivation. Therefore this seems a dubious headline.
The word "toxin" has become a signal for pseudoscientific medicine, so I also furrowed my brow at that. But the original use of the word is much more clear in context. From the abstract which tokenadult kindly linked to:
Thus, the restorative function of sleep may be a consequence of the enhanced removal of potentially neurotoxic waste products that accumulate in the awake central nervous system.
Sleep deprivation reduces learning, impairs performance in cognitive tests, prolongs reaction time, and is a common cause of seizures (3, 4). In the most extreme case, continuous sleep deprivation kills rodents and flies within a period of days to weeks (5, 6). In humans, fatal familial or sporadic insomnia is a progressively worsening state of sleeplessness that leads to dementia and death within months or years (7).
> A "toxin" is something which is toxic to a system. But our knowledge of the brain is so primitive that we can't reasonably claim to know which chemicals are toxic at tiny, long-term dosage levels, unless it leads to death.
If it leads to harm or death of individual neurons, we have lots of knowledge about such things. For example, we know that glutamate is toxic in large doses to neurons,
If you don't sleep for long enough (about 7 days), you'll start to have visual and auditory hallucinations and also delusional thinking. You'll also experience severely reduced effectiveness of just about every system in your body. You might not die if you don't sleep for a year (say), but you'll probably get permanent brain damage.
When I hear "toxins", I think of a developer on a project I helped manage. He was having health problems so he had to take a 1-1.5 month sabbatical to India to be cleansed of toxins. If I remember correctly the end result was that he quit.
While I do believe there that the body cleanses itself from toxins, and I can't say for certain whether the developer that left us got his toxins cleansed or not, this article and study smells of B.S.
The second tip off is the quoted doctor's name: Dr. Nedergaard
Scientists with Dutch/Scandinavian names always seem to produce the most crap science on average in my experience. I have no idea why, but I've noticed it. Especially when it comes to the "positive affects" of pot. I know that is an over-generalization, but someone should do a study on that to see if it's true. Preferably one without as many A's in his/her last name.
Well the trophy for most BS per capita definitely goes to the Chinese.Unfortunately If I see a chinese name on an IEEE article and it's not from a reputable university, I skip it.
As for clearing out toxins. It's been known for years that sleep clears free radicals from the brain. That's why very long term sleep deprivation can led to brain damage, and why if you take modafinil you aren't shielded from the physiological adverse effects of sleep deprivations (though mentally you'll be fine).
[+] [-] tokenadult|12 years ago|reply
http://news.sciencemag.org/brain-behavior/2013/10/sleep-ulti...
and that links to the abstract
http://www.sciencemag.org/content/342/6156/373
of the published study itself.
[+] [-] anishkothari|12 years ago|reply
http://www.urmc.rochester.edu/news/story/index.cfm?id=3956
[+] [-] elwell|12 years ago|reply
[+] [-] drewcrawford|12 years ago|reply
It turns out that the β-amyloids that are cleared during sleep according to this paper, are associated with certain types of dementia in the general population [2].
It also turns out that certain sleep disorders are dementia predictor [3].
This is just a laymen's speculation, but this is suggestive that dementia may be a type of sleep disorder, that it could be caused by some interruption in the process demonstrated in this paper.
And this is a stretch, but it is known that FFI is caused by a malformed prion protein, which is a protein that is deeply involved in various neuron-related functions. It seems possible that this protein is involved in the cleansing process in some way. If so, that would be a HUGE deal, because abnormal prion proteins are associated with a huge variety of neurodegenerative diseases.
Basically, I have high hopes for future research.
[1] http://en.wikipedia.org/wiki/Fatal_familial_insomnia
[2] http://www.ncbi.nlm.nih.gov/pubmed/17502554
[3] http://www.medscape.com/viewarticle/781136
[+] [-] drited|12 years ago|reply
Sources: http://www.webmd.com/alzheimers/news/20080610/bright-light-i...
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3553247/
[+] [-] srd|12 years ago|reply
I ask because due to allergies I have constant sinus congestions and as a result a very light sleep. On average I wake up (to the point where I'm consciously aware that I'm awake) 2 to 4 times per night, persumably due to lack of oxygen.
I'm noticing memory issues; and while the process may not be reversable, I would like to halt it or at least slow it down as much as possible.
[+] [-] foxhill|12 years ago|reply
[+] [-] Locke1689|12 years ago|reply
[+] [-] fsckin|12 years ago|reply
[+] [-] daenz|12 years ago|reply
[+] [-] dbecker|12 years ago|reply
Sure sounds like part of the wake-sleep algorithm, which is impressive given that the wake-sleep algorithm was named in the mid-90s.
[+] [-] dsrguru|12 years ago|reply
As any lucid dreamer can tell you, there's also a third option--asleep and aware.
[+] [-] samstave|12 years ago|reply
[+] [-] willstepp|12 years ago|reply
[+] [-] Technophobe|12 years ago|reply
If we could get the actual sleeping time to 1 minute, but keep the rest the same, surely that would be strictly better in terms of human utility.
[+] [-] tannerc|12 years ago|reply
[+] [-] j-g-faustus|12 years ago|reply
I suppose that the brain cells can't shrink that much while retaining their full function.
[+] [-] jared314|12 years ago|reply
[+] [-] scotty79|12 years ago|reply
[+] [-] brickcap|12 years ago|reply
Sleep also lowers the heart beat. It is generally accepted that all mammals have the same life span in number of hear beats. An elephant lives longer than a mouse because it's heart beats slower. Could that mean that people who live longer generally sleep more.
Whales are known to live for a long time. Wonder how much they sleep.
[+] [-] joshuahedlund|12 years ago|reply
Please note that while there is some correlation it may not be strict enough to suggest that lowering your own heart rate will help you live longer.
http://skeptics.stackexchange.com/questions/5701/does-every-...
[+] [-] batgaijin|12 years ago|reply
I mean there are stories of people with half their brain removed who are fully functional (I think? I can't find a source atm).
I wonder what would happen if half your brain could be on/off and switch?
Also you'd think that any mutation optimizing for time awake would have decimated the other creatures? I don't get how evolution has conquered everything but sleep.
[+] [-] whateverfor|12 years ago|reply
There are creatures that sleep very little (Giraffes, etc.) But there's large benefits to sleep, and for most animals it's worth the cost, especially since you don't want to burn piles of calories during non-peak hunting/foraging hours anyway.
[+] [-] soneca|12 years ago|reply
I think half brain awake is not enough to have a fully functional life. I also heard about people losing part of their brain and adapting to deal with it. But that doesn't mean a brain doesn't need that part. It is like the fallacy of using only 10% of the brain. The brain is very well used and optmized for performance, if you lose part of it, it would adapt to compensate what is missing, but it will not be optimized anymore.
Disclosure: just guessing here, I have no scientific knowledge or background at all to support these claims of mine.
[+] [-] drited|12 years ago|reply
For humans with 2 healthy hemispheres, as far as I'm aware better imaging is revealing that split brain theory is only partially correct for many of the processes that were formerly thought to happen in one half only. Recent imaging has shown that the other half is still involved, albeit in a less widespread fashion.
[+] [-] emiliobumachar|12 years ago|reply
Maybe the specialization into day/night has something to do with it. The decimator would need to stand their ground against nocturnal creatures at night and diurnal creatues at day.
[+] [-] greenyoda|12 years ago|reply
https://en.wikipedia.org/wiki/Glymphatic_system
The brain and spinal cord have no lymphatic circulation, which handles waste removal for the rest of the body.
[+] [-] Miyamoto|12 years ago|reply
[+] [-] jessriedel|12 years ago|reply
[+] [-] nikatwork|12 years ago|reply
I'm afraid this will require nanobots.
[+] [-] jotm|12 years ago|reply
[+] [-] jimgardener|12 years ago|reply
[+] [-] mkessy|12 years ago|reply
[deleted]
[+] [-] sillysaurus2|12 years ago|reply
[+] [-] scott_s|12 years ago|reply
Thus, the restorative function of sleep may be a consequence of the enhanced removal of potentially neurotoxic waste products that accumulate in the awake central nervous system.
Also, regarding the dangers of sleep deprivation, the first paragraph of the paper are relevant (http://www.sciencemag.org/content/342/6156/373.full):
Sleep deprivation reduces learning, impairs performance in cognitive tests, prolongs reaction time, and is a common cause of seizures (3, 4). In the most extreme case, continuous sleep deprivation kills rodents and flies within a period of days to weeks (5, 6). In humans, fatal familial or sporadic insomnia is a progressively worsening state of sleeplessness that leads to dementia and death within months or years (7).
Reference 7 is http://www.thelancet.com/journals/laneur/article/PIIS1474-44..., but I found the Wikipedia article more consumable for someone who is not up on medical research: http://en.wikipedia.org/wiki/Fatal_familial_insomnia
[+] [-] rusew|12 years ago|reply
[+] [-] azakai|12 years ago|reply
If it leads to harm or death of individual neurons, we have lots of knowledge about such things. For example, we know that glutamate is toxic in large doses to neurons,
http://en.wikipedia.org/wiki/Excitotoxicity
[+] [-] foobarbazqux|12 years ago|reply
[+] [-] rosser|12 years ago|reply
Perhaps not directly, as the actual cause of death in FFI is unknown, but:
https://en.wikipedia.org/wiki/Fatal_familial_insomnia
[+] [-] TaiChiChaiTea|12 years ago|reply
[+] [-] hkon|12 years ago|reply
[+] [-] giardini|12 years ago|reply
[+] [-] o0-0o|12 years ago|reply
[deleted]
[+] [-] _-_-_-|12 years ago|reply
While I do believe there that the body cleanses itself from toxins, and I can't say for certain whether the developer that left us got his toxins cleansed or not, this article and study smells of B.S.
The second tip off is the quoted doctor's name: Dr. Nedergaard
Scientists with Dutch/Scandinavian names always seem to produce the most crap science on average in my experience. I have no idea why, but I've noticed it. Especially when it comes to the "positive affects" of pot. I know that is an over-generalization, but someone should do a study on that to see if it's true. Preferably one without as many A's in his/her last name.
[+] [-] anotheraccount7|12 years ago|reply
As for clearing out toxins. It's been known for years that sleep clears free radicals from the brain. That's why very long term sleep deprivation can led to brain damage, and why if you take modafinil you aren't shielded from the physiological adverse effects of sleep deprivations (though mentally you'll be fine).